Abstract: Multi-path error remains a key issue in the BDS baseline solution,as it cannot be eliminated by differential methods and significantly affects the accuracy of the solution.To mitigate the impact of multi-path error,two modeling approaches are commonly employed.In this study,we use a short baseline composed of two stations,Delta park station and Yinghe east road station,from the Fuyang subsidence monitoring project in Anhui province to conduct experiments.We collect actual BDS observation data and compare the effectiveness of the two methods in reducing multipath error for subsidence monitoring applications.The results indicate that both methods improve the baseline accuracy.The first method achieves improvement rates of 76.47%,71.95%,and 72.61%in the E,N,and U directions,respectively.The second method shows improvements of 65.73%,61.38%,and 59.60% in the E,N,and U directions,respectively.

Key words: BeiDou Navigation Satellite System, multipath error, sidereal filtering, multipath hemispherical map method, settlement monitoring